selenium toxicity in animals

Selenium (Se) is an essential element for many animals includ-ing humans, prokaryotes and a few green algae. Since high levels of selenium are used as cancer chemopreventive agents in animals and humans, a better understanding of the metabolism of subtoxic levels is desirable. Serious and life-threatening selenium toxicity can and does occur but is incredibly rare among humans. soil selenium area in China was reported to contain 50–160 µg/l (IPCS, 1987). In alkaline soils, selenite undergoes oxidation into a more soluble form that is easily assimilated by plants (selenite). Selenium (Se) toxicity is a serious threat when an excess of it is found in soils. This edition supersedes any previously released draft or final profile. horses. Sodium selenite is the most toxic compound on oral ingestion. Selenium sulfide has been linked with the occurrence of liver and lung tumors in mice and rats following oral exposure, and is a Group B2 carcinogen as per EPA classification. Elemental selenium has low toxicity following oral administration. Introduction. 2.3 Food Most people obtain virtually all of their selenium from the foods they eat. Several metabolic disorders have been reported due to the dietary deficiencies of selenium and vitamin E in several species like chickens ( Schwarz et al ., 1957 ), turkeys ( Scott et al ., 1967 ), rats ( Schwarz and Foltz, 1957 ), calves, lambs with several health disorders. This can build up in the plants and injure the livestock that feed on them. Affected animals are dull, very thin, and lack energy. Is Selenium Toxicity a Concern for Our Pets? SELENIUM iii . Usually, death occurs within a few hours. Selenium poisoning and toxicity has no treatment / antidote; hence, it is very vital to rush to the emergency room and get prompt medical aid if symptoms become apparent. The most vital aspect of the treatment is supportive care, managing the symptoms effectively and preventing a further exposure. It's much more common in livestock because the primary source of selenium depends on soil concentrations. Chronic (longterm) selenium poisoning, also called alkali disease, usually develops when animals (livestock and horses) consume forages and grains containing selenium for many weeks or months. Taking too much selenium over time can lead to selenosis, which can cause hair loss, nail loss, nausea, irritability, fatigue and some nerve damage. Other symptoms of chronic selenium overdose are a metallic taste in the mouth, and a garlic scent on the breath. Between 10% to 40% of animals die of this condition (Andrews A. H., 1992). Some symptoms are more severe than others, but all represent a disruption in wellness. (z9' Chronic selenosis of the alkali disease type, in which the animals ate grains and/or forages con- taining in the order of 5 to 30 ppm of selenium over a period of several weeks or months, exhibiting, A balanced diet is a key to a happy and healthy life for your dog, and part of that balanced diet includes critical trace minerals. in animals on the rate of methylation and its excretion. and swine is characterized by an abnormal posture. of selenium. Although it is toxic in large doses, selenium is an essential micronutrient for animals. development of animals. In animals, selenium toxicity has also been associated with abnormal fetal development in cattle, swine, and sheep, but with infertility and a higher proportion of runt offspring and fetal deaths. Pockets of seleniferous soils have been identified in north eastern parts of Punjab, India, by examining the Se content of soils, irrigation water, plants and animal tissues. Selenium (Se) is an essential micronutrient for humans and animals, but lead to toxicity when taken in excessive amounts. However, if given in too large a dose or more than one supplement containing selenium is given at the same time, it can be toxic. Selenium (Se) toxicity in domestic animals can be acute or chronic. For plants, Se essentiality is yet to be demonstrated. This is because runoff from the soil causes selenium to collect in the water in high levels and then starts working its way up the food chain and causing problems, as shown in the following link. So, our traditional nonruminant species are … There are various areas of the country that are deficient in Selenium and other areas that have toxic levels. A Toxicological Profile for selenium, Draft for Public Comment was released in September, 2001. The toxic effect of selenium on animals occurs on these soils [ 26, 27 ]. Young animals are most susceptible to acute parenteral selenium toxicosis with dosages of 0.2–0.5 mg/kg. However, selenium in greater than minute (trace) amounts is toxic to human and animal life. Selenium is one of a group of trace minerals that is essential for proper body functions in both humans and animals. In plant and animal tissues, selenium is found mostly bound to proteins. Younger animals tend to be more susceptible to selenium poisoning, … Symptoms of selenium toxicity include nausea; vomiting; nail discoloration, brittleness, and loss; hair loss; fatigue; irritability; and foul breath odor (often described as “garlic breath”).1,2,4–6. Animal responses to toxic amounts of selenium are highly variable as it involves the time dose response relationship. Parenteral selenium products are also quite toxic, especially to young animals, and have caused deaths in piglets, calves, lambs, and dogs at dosages as low as 1 mg/kg. As little as 7.2 parts per million of selenium in the ration in the natural form and 10 parts per million as added sodium selenite were toxic as shown by sub-normal growth and restricted food intake. Severity of Se poisoning depends on chemical forms of the … increased ouise and respiratory rate. Pacific Northwest soils are generally low in Selenium, as are feeds that are grown here. The literature on clinical signs and toxicity data for acute and for chronic selenosis in farm and experimental animals is discussed. 1. [Selenium toxicity in domestic animals] The earliest written report of selenium poisoning is thought to be the description by Marco Polo of a necrotic hoof disease of horses that occurred in China in 13. century. The selenium content of soil affects the amounts of selenium in the plants that animals eat, so the quantities of selenium in animal products also vary [2,5]. Several cases of acute selenosis in man are reviewed, and a number of reports on chronic selenosis in man are reviewed and evaluated. It turns out, because of the unique differences in the digestive tracts of our ruminant species, like sheep and goats and cattle, they are less sensitive to selenium toxicity than, say, you or I, or a horse, or a pig, or poultry. Poisoning in cattle. The calf may stand and move stiffly. Young, growing animals are rapidly creating muscle mass, so Selenium deficiency shows itself most commonly as muscle cell degeneration. Selenium toxicity is often caused by over-supplementation and can impact the human body in a number of ways. Thus, if death occurs rapidly, the signs may vary from those seen if death occurs some time after eating a lethal amount of Therefore, the most important food sources of selenium are meats and seafood (0.3–0.5 mg/kg), because and death. locoweed.Selenium is a component of the amino acids selenocysteine and selenomethionine.In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. The signs depend on the muscles affected. Selenium (Se) is a metalloid in group VIA and an analog of sulfur, with four oxidation states in nature: selenate (+ 6), selenite (+ 4), elemental selenium (0), and selenide (− 2) (Tinggi, 2003).Unlike As, Se is an essential nutrient for humans, animals, and bacteria. Six seleniferous sites were identified on the basis of Se levels in wheat and sugarcane in the north eastern parts of Punjab, India. Absorption from rat small intestine using in situ double perfusion, ligated intestinal segments, and brush border membrane vesicles (BBMV) was used to study selenium absorption. According to the Agency for Toxic Substances and Disease Registry, people who consume crops, vegetables or animal products in these regions could be exposed to too much selenium. A study of chronic selenium poisoning in dogs has been made using a basic ration high in grain. Acute selenium poisoning may be produced in lambs given a single injection of 5 mg of selenium. Selenium (Se) is an important nutrient in animal and human nutrition. The rate of soil acidity determines the amount of selenium in crops and plants; more selenium is released in alkaline soil than in acidic ones. diarrhea, abdominal pain. Before we go further let us check the definition of Se in a medical dictionary (Merriam-Webster, 1996). 66 Rangelands 6(2), April 1984 Pigs previously given a selenium-deficient diet are more susceptible to acute intoxication than are normal pigs. Animals suffering from selenosis were found to have decreased levels of vitamin A, and ascorbic acid.25 Ip, reported that the protective effect of selenium on mammary carcinoma in animals was nullified by high vitamin C supplementation.26 Selenium toxicity in laboratory animals … • Long-term exposure to selenium, sodium selenite, sodium selenate, or selenium dioxide may cause paleness, coated... • According to the 1986 edition of the Handbook of the Toxicology of Metals, daily intake of about one milligram of... • … It is very important in animal nutrition because it functions as an anti-oxidant assisted by vitamin E. Se deficiency is a major problem which can be reduced or prevented by supplementation with inorganic or organic sources of Se. 11 Symptoms of Selenium Toxicity. According to FDA, the minimum dietary requirement for selenium ranges from 0.1 to 0.5 parts per million (ppm), depending on animal species, age, and other factors. Selenium (Se), an essential nutrient for animals and humans, occurs as selenoproteins in enzymes. prostration. Often all that will be seen in sheep is depression and sudden death. For all organisms, while, a narrow range of Se is beneficial, at ele-vated levels it becomes toxic. However recognition of Se as toxic principle come in the early 1930s. Cattle and sheep arethe most likely species to be affected, but also horses, goats, and swine.Studies have shown … Selenium toxicity can be a problem, especially for animals living in or around a body of water in an area with high soil selenium levels. In fact, high doses of selenium can be quite toxic, and a majority of scientific research into selenium was originally focused on its toxicity, not on its benefits. UPDATE STATEMENT . In plants, it sometimes occurs in toxic amounts as forage, e.g. Acute poisoning is caused by the consumption, usually in a single feeding,of a sufficient quantity of highly seleniferous plants, which produce severesymptoms. The role of Selenium -Selenium is another essential trace element required in a dog’s diet, but at a much lower level than that of zinc. The … Plants are the main source of dietary Se, but essentiality of Se for plants is still controversial. It is required in cattle for normal growth and fertility and for helping to prevent other health disorders such as mastitis and calf scours. Clinical signs are different from those of chronic selenosis and are characterized by abnormal behavior, respiratory difficulty, GI upset, and sudden death. If animals are consuming soil which is heavily concentrated in selenium then they may start to experience signs of excess. Exact mechanism of selenium toxicity remains unclear but there are many data about its prooxidant Sneeo do not snow si gns of selenium poisoning as distinctly as do other species 01 domestic animals. This can occur when the wrong selenium preparation is used for injection and with over generous administration. There is some question, however, that selenium is the cause of this syndrome. At all the toxic sites, typical Se toxicity symptoms appeared in wheat with Se content ranging from 99.1 to 451.0mg/kg. Several factors are known to alter selenium toxicity; however, in general, a single acute oral dose of selenium in the range of 1–10 mg/kg may be lethal in most animals. Subacute muscular dystrophy, also known as white muscle disease, is the most commonly seen form of selenium deficiency in calves. Acute toxicity, with high mortality in sheep, has been described following incorrect use of sodium selenite injections (Kyle and Allen 1990), or of anthelmintic drenches containing Se compounds. The toxic dose of selenium by injection for both cattle and sheep is in the region of 1 mg/kg. In vitro studies showed that there are selenium-resistant animal and human cell lines which showed altered selenium uptake. The early history of selenium poisoning is briefly summarized. Toxic sites ranging from 4 ‐ 16 ha were sporadically distributed in the study area and occupied more than 100 ha. Nevertheless, it is well recognized that Se is a beneficial element for plants. Selenium is found in the environment in soil. In addition to the naturally occurring selenium species, animal feeds may contain various selenium compounds added during production to raise the level of total selenium in the animals… selenium. unsteady gait. Selenoamino acids are considered to be less toxic than the inorganic forms, with Se(IV) being the most toxic species [6]. Selenium is a mineral essential in small amounts for thyroid and immune system function. It also acts as an antioxidant, helping prevent cell damage by free radicals. Consuming sufficient amounts of selenium may lower your risk for heart disease and cancer, but consuming excessive amounts of selenium can be harmful. Selenium (Se) is now recognised as an essential trace element for ruminants. However, Se at low doses protects the plants from variety of abiotic stresses such as cold, drought, desiccation, and metal stress. SELENIUM TOXICITY. Selenium-a nonmetallic element that resembles sulfur and tellurium chemically, causes poisoning in range animals …